Lasers produce light having a distinct frequency. The frequency of the light is directly related to the type of material the laser is made of and the corresponding energy that is released when electrons of the material fall to a more stable level from a less stable or more excited state. Since existing material may only lase at a limited number of frequencies, there is a need to be able to shift the produced light to a more desired frequency for various applications.
Recently, the use of magnetostatic waves to mode couple with light in a thin film has been demonstrated. See, U.S. Pat. No. 4,575,179 to Lee, et al. Therein there is taught the use of magnetostatic waves to diffract the light in proportion to the magnetostatic wave. The amount the light is diffracted can be determined and thus the signal producing the magnetostatic waves can be identified. However, Lee, et al. does not teach or disclose a way that magnetostatic waves can be used to shift light to a desired frequency over a broad range.